Stone Fruit Crops Research Articles

Determination of residual amounts of chlorothalonil in peaches: problems of gas chromatographic identification with the use of electron capture detector

In the work there are presented results of studies on the validation of the gas chromatographic (GC) methodfor the determination of chlorothalonil residue amounts in peaches with the use of electron capture detector (ECD). For the analytical control there was selected such stone fruit crop as the peach, referring to the crops, the most contaminated with residue amounts ofpesticides. There was justified the necessity of the inclusion in the procedure of the detection of the method of confirmation, based on mass spectrometry detection (MSD) (the type of ionization - electron impact). The significant source of the obtaining of incorrect data in the identification with the use of ECD of ions are shown to be phthalates, visualized in the chromatogram as intense and/or broad peaks. Mass spectra of compounds of the class ofphthalates are characterized by the dominant peak of the ion with the value of (mass/ charge) 149, just on this peak the detection of low molecular weight phthalates occurs in various matrices, on the spectrum there are also recorded typical ions corresponding to fragments of radical residues. The combination of the use of various types of the detection allows to prove that the revealed response (detector signal) is caused just by the analyte, but not the impurities, and optionally to optimize chromatographic conditions towards to the obtaining reliable results. The lower limit of the quantitation of chlorothalonil in peach fruits accounts for 0.01 mg/kg, determined with a signal/noise ratio of 10. The range of measured concentrations is volatile between 0.01-0.1 mg/kg, recovery rate of chlorothalonil from samples of peaches, established according to results of the analysis of model samples with the introduction of the substance in four points along the detection range, was 84-102%, the SD value of the repeatability varies in the range of 2.0-5.8%.

Modern information about fungal pathogens on stone fruit crops in the western part of the Black Sea coast of Krasnodar region

Modern information about fungal pathogens on stone fruit crops in the western part of the Black Sea coast of Krasnodar region

Improving the technology of obtaining clonal root stocks of stone fruit crops

The aim of the research was to study the effect of the cuttings rooting period on the yield of high-quality rootstocks of stone fruit crops. In accordance with the developed methodology of research, modern rootstocks of stone fruit crops on the Crimean selection station Eureka 99 and Kuban 86 for plum, apricot, peach, and also VSL-2 for cherry and sweet cherry were studied. The paper presents the results of three-year experiments on the study effect of the rooting period hardwood cutting for standard stone seed root stocks. The data of mathematical processing the obtained results indicate the rooting period has a significant impact on the survival of hardwood cuttings. During the experiment, the average for the studied rootstocks during the autumn period of rooting, the survival rate of the cuttings was significantly higher than for the spring by 2.8%. According to the obtained data, on average, in terms of rooting for the stock Eureka 99, the highest survival rate of cuttings in experience was observed, significantly exceeding the figure of the other rootstocks by 21, 1-25, 4%. Output rates of standard rootstocks were adequate for the number of rooted cuttings. The results given in the article indicate that rootstocks Eureka 99 and VSL-2 have the highest yield of rootstocks per hectare observed during the spring planting season, exceeding the autumn planting dates by 109 and 217 thousand pieces respectively. The Kuban 86 rootstock has a reverse pattern. The article presents the results of sorting the obtained rootstocks by quality degrees. According to the data obtained, the highest yield of the first grade seedlings in the experiment was observed on almost all variants during the autumn term of rooting.

Understanding the Process of Latent Infection of Canker-Causing Pathogens in Stone Fruit and Nut Crops in California.

The Botryosphaeriaceae family is considered a fungal family that includes pathogens causing latent infection of woody plants, and a number of species were identified as causal pathogens of canker and shoot blight diseases. To better understand the process of latent infection of major canker-causing pathogens in woody tissues in different tree crops important in California, shoot and bud samples were randomly collected from four tree crops: almond, dried plum, pistachio, and walnut. The previously developed DNA primers and quantitative real-time PCR (qPCR) assay systems were applied to detect six canker-causing pathogen groups, including Botryosphaeria dothidea, and species of Cytospora, Diplodia, Lasiodiplodia, Neofusicoccum, and Phomopsis. The concepts of molecular severity (MS) and latent infection index (LII) were introduced and applied to quantify the latent infection levels for these samples. Variation in incidence of latent infection among pathogen groups was observed, whereas the incidences were relatively low among species of Phomopsis and Diplodia. High incidences of Cytospora spp. were observed in two dried plum (prune) orchards. Most orchards showed high incidences of B. dothidea and Lasiodiplodia spp. and moderate incidences of Neofusicoccum spp. Variations in MS were observed among samples of the studied orchards, ranging from 4 to 8. The overall results of LII demonstrated that species of Diplodia and Phomopsis were less important in population development of canker-causing pathogens at the latent phase. Lasiodiplodia spp. were the most aggressive and had been well developed in populations among the studied tree crops. Cytospora spp. became predominant in two of the three dried plum orchards, whereas B. dothidea and Neofusicoccum spp. showed trends of increase in incidence across various tree crops. This study also demonstrated the usefulness of this sensitive qPCR approach in providing evidence of the latent phase of major canker-causing pathogens of stone fruit and nut crops at an early stage of latent infection in woody plant tissues.

ЭФФЕКТИВНОСТЬ АНТИБИОТИКОВ В ОЗДОРОВЛЕНИИ МИКРОКЛОНОВ ПОДВОЕВ MAXMA 14, GF 677, MYROBALAN 29C ОТ ИНФЕКЦИЙ РАЗЛИЧНОЙ ЭТИОЛОГИИ

The article presents experimental data on the effectiveness of various groups of antibiotics in the rehabilitation of the explants of some rootstocks of stone fruit crops from infections of various etiologies brought from the environment, in violation of the rules of sterility in working with an in vitro culture. The results of the study showed that the morphogenetic response of explants of clonal rootstocks to antibiotics depends on their varietal origin. Thus, a greater number of the introduced explants Myrobalan 29C necrotic (25-100%). The number of normally developed microplants for different rootstocks ranges from 0 to 75. It was found that all studied antibiotic concentrations, except ceftriaxone 10 mg/l and nystatin 100 mg/l, positively affect the viability of MaxMa 14. For rootstocks Myrobalan 29C maximum the number of viable explants (60% of healthy explants) showed the environment with the antibiotic nystatin at a concentration of 200 mg/l. For rootstocks GF 677, the maximum number of well-developed micro shoots was observed on nutrient media with antibiotics tetracycline at a concentration of 100 mg/l and ceftriaxone at a concentration of 200 mg/l (60% of healthy explants in both variants).

ЭКОНОМИЧЕСКАЯ ЭФФЕКТИВНОСТЬ ВЫРАЩИВАНИЯ ПЕРСПЕКТИВНЫХ КЛОНОВЫХ ПОДВОЕВ КОСТОЧКОВЫХ КУЛЬТУР МЕТОДОМ ТРАВЯНИСТОГО ЧЕРЕНКОВАНИЯ

ЭКОНОМИЧЕСКАЯ ЭФФЕКТИВНОСТЬ ВЫРАЩИВАНИЯ ПЕРСПЕКТИВНЫХ КЛОНОВЫХ ПОДВОЕВ КОСТОЧКОВЫХ КУЛЬТУР МЕТОДОМ ТРАВЯНИСТОГО ЧЕРЕНКОВАНИЯ

Complete mitochondrial genome of plant pathogen Monilinia fructicola (Sclerotiniaceae, Helotiales)

Monilinia fructicola is a plant pathogenic fungus usually causing brown rot in the stone fruit crops. Here, the complete mitochondrial genome of M. fructicola is first reported, and the length of the circular genome was 163,790 bp and the content of GC was 31%. Meanwhile, it contained 28 transfer RNA (tRNA) genes, 30 protein-coding genes (PCGs) with many intron sequences and 2 ribosomal RNA (rRNA) genes. Phylogenetic analysis with 15 Leotiomycetes species indicated that M. fructicola was clustered in the Sclerotiniaceae family and was closely narrowed to Botryotinia fuckeliana and Sclerotinia scleroticrum. In addition, the valuable gene information of the mitochondrial genome was provided, and the study on the control of this destructive pathogen would be facilitated.

Response of orchard floor management treatments to soil hydrothermal regimes in nectarine

Being the second important stone fruit crop of Himachal Pradesh, nectarine still requires a great improvisation in floor management. Keeping this objective, a two year study was conducted with various orchard floor management practices on eight year old ‘Snow Queen’ nectarine trees during 2014 and 2015. The experiment was laid out in Randomized Block Design, having seven treatments including control and replicated four times. Among all treatments soil hydrothermal regimes were maintained effectively under grass mulch and black polythene mulch. Grass mulch recorded maximum increase in annual shoot growth (148.25 cm), per cent increase in trunk girth (11.49%), per cent increase in tree height (14.46%) and per cent increase in tree volume (40.84%). Maximum fruit set (74.38%) and fruit yield (26.09 kg/tree) was recorded under nylon mulch mat while minimum fruit drop (16.37%) under grass mulch. Bicolour polythene mulch recorded fruit size (56.90 mm), fruit weight (100.97 g), fruit volume (102.94 cc), pulp to stone ratio (14.65), TSS (12.91 oBrix), total sugars (9.58%) and reducing sugars (4.10%) along with maximum proportion (82.25%) of “A” grade fruits.

ИСПОЛЬЗОВАНИЕ ДИКОРАСТУЩИХ ВИДОВ PRUNUS L. В СЕЛЕКЦИИ СЛАБОРОСЛЫХ АДАПТИВНЫХ ПОДВОЕВ ПЕРСИКА

All modern technologies of peach cultivation are focused on the use of clonal, mainly dwarf, rootstocks. Technical efficiency and resistance to pathogens are also important. The work on the creation of such clonal rootstocks of peach is carried out at the Krymsk Experiment Breeding Station (EBS), a branch of VIR, on the basis of the stone fruit crop genetic diversity accumulated at the Station, primarily using the wild species which can serve as donors and sources of important breeding traits. The studied fruit crop genetic diversity was found to contain the most promising genotypes, for instance dwarf P. pumila L., P. tomentosa Thunb., P. ulmifolia Franch., P. pedunculata Maxim., P. tenella Batsch (= Amygdalus nana L.) and P. petunnikowii Rehd.; soil pathogen-resistant genotypes, e.g., P. davidiana Franch. and its hybrids Barrier (P. davidiana x P. persica Stokes)), Sputnik (P. kansuensis Rehd. x P. davidiana), Major (P. amygdalus Stokes x P. davidiana), etc.; chlorosis-resistant genotypes: Kuban 86 (P. cerasifera Ehrh.x P. persica), VSV 1 (P. incana (pall.) Roem. x P. tomentosa Thunb.); as well as the genotyopes that display easy rooting of the lignified cuttings, e.g., P. cerasifera Ehrh., P. pumila L., Kuban 86, etc. Of great interest are the recently developed dwarf, adaptive and productive rootstocks, such as Best (P. pumila x P. cerasifera) and Uprjamec (P. cerasifera x P. ulmifolia). The testing of new clonal rootstocks has shown their suitability for the use in peach plantations cultivation applying modern intensive technologies, and for the production of peach planting material using intensive technologies. The State Register of Breeding Achievements Approved for the Use in the Russian Federation includes such clonal rootstocks of peach as Kuban 86, Evrika 99, VVA 1, VSV 1, Best and Zarevo. The clonal rootstock Uprjamec has been accepted for the state trials.

АНАЛИЗ ЖИЗНЕСПОСОБНОСТИ ПЫЛЬЦЫ АБРИКОСА И ЧЕРЕШНИ ПОСЛЕ КРИОКОНСЕРВАЦИИ

Cryopreservation minimizes the risk of losing valuable accessions and reduces the material costs of plant resources maintenance. By using the method of pollen long-term storage in cryobanks, it is possible to keep pollen grains viable for an unlimited time. In the course of the research, cryoconservation of pollen of stone fruit crops was performed and pollen viability was checked after exposure to ultra-low temperatures (-196°С) under laboratory conditions. The studies were carried out on apricot (Armeniaca vulgaris Lam.) and sweet cherry (Cerasus avium (L.) Moench) plants, from which pollen was collected. Evaluation of viability in laboratory conditions was carried out by germination on various nutrient media. The possibility of long-term pollen preservation in liquid nitrogen vapor is shown. Based on the results obtained, a collection of pollen is being created for implementing various breeding programs.

Results of quantitative parameters evaluation of leaves of some fruit and berry Rosaceae cultivars and hybrids

The leaves of higher plants reveal a wide range of structural and ecofunctional differences expressed for taxa of various ranks, for representatives of ecological groups, as well as associated with adaptation to a complex of biotopic conditions. Among the quantitative indicators determined in the study of leaf phytomass samples there are some detected by direct measurement and others detected by calculating. The second group of indicators includes, in particular, the leaf mass per area (LMA) parameter. In nature, this indicator reveals differences within two orders for plants of various life forms (from the minimum in freshwater hydrophytes to the maximum in desert inhabitants). Functional groups of plants are characterized by unequal level of LMA plasticity in the gradient of abiotic conditions (such as light, temperature, moisture, edaphic regime). Evaluation of leaf apparatus parameters is widely demanded in various actual directions (plant ecology, forestry, environmental protection, cultivars study, etc.). In this paper we present some generalized data related to the results of the study of the leaf structure for some fruit and berry Rosaceae cultivars and hybrids (25 varieties of pears, 15 apple, 13 garden strawberries, 7 clone rootstocks for stone fruit crops), for which the Scientific Research Institute Zhigulevskiye Sady specialists carry out cultivars study. We performed a row ranking procedure and constructed distribution histograms for the integrated data blocks for each group of objects, using the Excel. We turned to the percentage of the proportion of variables corresponding to different levels of LMA. The distribution analysis of generalized data on the LMA index showed perspectivity for comparing groups of objects of different systematic (varietal) accessories and for detection of dissimilarity trends between them.

Certification of stone fruit crops in Ukraine

The results are the work during 2004—2018 years in Ukraine on the selection of material of stone fruits crops, which satisfies the requirements of the normative international documents for the creation of a prebasic clones collection. Analyzed state of plant material certification of these cultures.

Evaluation of a New Machine for Flower and Fruit Thinning in Stone Fruits

Peach and apricot trees usually set more fruit than they can adequately support. Crop load adjustment through fruit thinning is a routine practice adopted by fruit growers to obtain a marketable product. However, hand thinning is an expensive, labor-intense operation. The interest in the mechanization of thinning has increased in the last decades. A new machine, consisting of a tractor-mounted rotor equipped with elastic rods radially inserted on a central axis, has been recently developed to thin both flowers and green fruits in stone fruit crops. In order to test its effectiveness and optimize the operative conditions, trials were carried out in 2016 in two apricot and two peach commercial orchards located in the northeast Italy. Tests were carried out on narrow-canopied orchards, during blooming time, and on green fruit, assessing the flower and fruit removal percentage and the labor saving as compared with the standard fruit hand-thinning practice. In apricot, the machine removed 20.8% of flowers and 43.6% of fruit, allowing 48% time saving in the follow-up fruit manual thinning as compared with the control (hand-thinning only). In peach, mechanical thinning at blooming time removed 63% of flowers, allowing 42.4% time saving in the follow-up fruit manual thinning as compared with the control, whereas mechanical thinning of fruit at the beginning of pit hardening stage removed less than 10%. The development of a mechanical thinning practice, complemented by a manual finishing, could represent a valuable near-term solution to reduce thinning labor time.

Sequence Analysis of Plum pox virus Strain C Isolates from Russia Revealed Prevalence of the D96E Mutation in the Universal Epitope and Interstrain Recombination Events.

The understanding of genetic diversity, geographic distribution, and antigenic properties of Plum pox virus (PPV) is a prerequisite to improve control of sharka, the most detrimental viral disease of stone fruit crops worldwide. Forty new PPV strain C isolates were detected in sour cherry (Prunus cerasus) from three geographically distant (700–1100 km) regions of European Russia. Analysis of their 3’-terminal genomic sequences showed that nineteen isolates (47.5%) bear the D96E mutation in the universal epitope of the coat protein. Almost all of them cannot be detected by the monoclonal antibody 5B in triple antibody sandwich enzyme-linked immunosorbent assay and Western blot analysis that may potentially compromise serological PPV detection in cherries. Full-length genomes of seven PPV-C isolates were determined employing next-generation sequencing. Using the Recombination Detection Program (RDP4), the recombination event covering the region from (Cter)P1 to the middle of the HcPro gene was predicted in all the available PPV-C complete genomes. The isolates Tat-4, belonging to the strain CV, and RU-17sc (PPV-CR) were inferred as major and minor parents, respectively, suggesting possible pathways of evolution of the cherry-adapted strains. Downy cherry (P. tomentosa) was identified as the natural PPV-C host for the first time.

Scents in orchards: floral volatiles of four stone fruit crops and their attractiveness to pollinators

Stone fruit crops grow in various regions around the world and are highly valued for their nutritional content, delicious taste, and economic importance, with an annual worldwide production of up to 42 million tonnes. In spite of their importance as a food resource, little is known about the chemistry of the floral volatiles of these crops, especially in relation to plant–pollinator interactions. In this study, the floral volatiles from four major stone fruit crops (apricot, Prunus armeniaca L.; plum, Prunus domestica L.; cherry, Prunus avium L.; and peach, Prunus persica L.) were collected and analysed by coupled gas chromatography/mass spectrometry (GC/MS). This was followed by several field trials, where selected floral volatiles were tested for attractiveness to flower visitors and pollinators. Twenty-six floral volatile compounds were identified in the headspace of the four Prunus spp. Benzaldehyde was present in the headspace of all four species. The norisoprenoid 4-oxoisophorone and lilac aldehyde were the main compounds in the headspace of P. armeniaca, P. domestica, and P. avium. The floral headspace of P. persica was distinct from the other three Prunus species, with 3,5-dimethoxytoluene being the most prominent compound (> 95%). In the field trapping trials, 4-oxoisophorone was attractive to various flower visitor species in a number of habitats when tested alone or in combination with benzaldehyde. Similarly, 3,5-dimethoxytoluene attracted several flower visitor species when tested alone or in combination with benzaldehyde. Our finding suggests that chemical cues are an important signal in plant–pollinator interactions in the four stone fruit species. This work provides the first detailed analysis of the floral volatiles of these important crops, especially in the context of plant–pollinator interactions. The floral compounds identified in this study could be used to enhance pollination of these important crops, either by direct application in the field (i.e. slow-release device) to enhance pollinator foraging or by training pollinators on such signature compounds to enhance flower visitation.

Reducing Drosophila suzukii emergence through inter-species competition.

Drosophila suzukii has dispersed widely from its native Asian range since 2008. Its arrival in the UK is resulting in economic losses in soft- and stone-fruit crops caused by larvae feeding on the flesh of ripening fruit. Although a large amount of research has been directed at controlling this pest, it is presently unknown how this invasive species interacts with native Drosophila species. In the work reported here, D. suzukii or Drosophila melanogaster adults were introduced to substrates pre-inoculated with the eggs of the same or the other species in a laboratory choice assay. Drosophila melanogaster adult emergence was not affected by pre-inoculation with D. suzukii. The rate of emergence of D. suzukii was significantly lower from medium pre-inoculated by D. melanogaster than from blank medium. In a subsequent experiment, significantly more D. suzukii eggs were laid in blank medium than in D. melanogaster pre-inoculated medium. The presence of D. melanogaster in a substrate significantly reduced D. suzukii emergence and egg laying. This study raises research questions about how this reduction mechanism is driven and how it could be exploited as part of future integrated pest management practices. © 2017 Society of Chemical Industry.

Non-Crop Host Sampling Yields Insights into Small-Scale Population Dynamics of Drosophila suzukii (Matsumura).

Invasive, polyphagous crop pests subsist on a number of crop and non-crop resources. While knowing the full range of host species is important, a seasonal investigation into the use of non-crop plants adjacent to cropping systems provide key insights into some of the factors determining local population dynamics. This study investigated the infestation of non-crop plants by the invasive Drosophila suzukii (Matsumura), a pest of numerous economically important stone and small fruit crops, by sampling fruit-producing non-crop hosts adjacent to commercial plantings weekly from June through November in central New York over a two-year period. We found D. suzukii infestation rates (number of flies emerged/kg fruit) peaked mid-August through early September, with Rubus allegheniensis Porter and Lonicera morrowii Asa Gray showing the highest average infestation in both years. Interannual infestation patterns were similar despite a lower number of adults caught in monitoring traps the second year, suggesting D. suzukii host use may be density independent.

Research Article New insights into the genetic diversity and species identification of the native apricots in Southern Xinjiang of China

Apricot is a staple stone fruit crop cultivated in Southern Xinjiang of China. This crop is important for the rural communities, as they generate significant employment and income. Here, seventy-eight apricot genotypes, including seventy-six common apricots (Prunus armeniaca L.) and two purple apricots (Prunus dasycarpa Ehrh.), were mainly collected from Aksu, Kashgar, Hetian and Bayingolin. Start Codon Targeted (SCoT) markers and ITS (internal transcribed spacers) sequences were used to investigate the genetic diversity and species identification respectively. Based on POPGENE showed that apricot cultivars from Aksu group exhibited the highest genetically diverse as compared with other groups, cluster analysis of SCoT markers (basede on UPGMA and PCoA method) showed that these apricot cultivars could be divided into three major clusters, which was in agreement with their geographic distribution and pedigrees. It was indicated that there were possible three primary diversity centers in the area: Aksu, Kashgar and Hetian, and also possible introgression among these populations. Furthermore, based on the complete ITS sequences, the phylogenetic analysis showed that P. dasycarpa clustered separated from other the section armeniaca of species. Therefore, it was proposed that P. dasycarpa would be a hybrid species. Our results indicated that SCoT markers are informative and could be used to evaluate genetic diversity of apricots, and ITS could be used effectively to identify P. dasycarpa. These results will provide much more useful information for the native apricots protection and utilization strategies.

СОВЕРШЕНСТВОВАНИЕ СОРТИМЕНТА КЛОНОВЫХ ПОДВОЕВ ДЛЯ КОСТОЧКОВЫХ КУЛЬТУР

СОВЕРШЕНСТВОВАНИЕ СОРТИМЕНТА КЛОНОВЫХ ПОДВОЕВ ДЛЯ КОСТОЧКОВЫХ КУЛЬТУР

First Report of Plum pox virus Strain M in Japan

Plum pox virus (PPV) is a causal agent of plum pox (sharka), the most serious viral disease for the stone fruit crops (Prunus spp.) (Garcia et al. 2014). Nine PPV strains are known, out of which strains D and M are the most widespread and economically important. In 2009, PPV-D was detected from Japanese apricots (Prunus mume) in Japan (Maejima et al. 2011). A nationwide survey was then started, followed by an eradication program. In the program, the collected samples were tested by a PPV immunochromatographic assay kit (NIPPON GENE, Japan), and only those with positive results were further tested by reverse transcription loop-mediated isothermal amplification method (RT-LAMP) using a PPV detection kit (NIPPON GENE). In June 2016, some Japanese apricots and apricot (P. armeniaca) trees were found with typical PPV symptoms such as ringspot and mottle on leaves, and some peach (P. persica) trees with mild mottle on leaves in Yokohama, Japan. These trees were distributed in a small area in Yokohama city. Most...